The invention relates to a connector for high frequency coaxial cables. It also relates to a bushing used in such connectors which can be inserted between the dielectric and the outer conductor of such a cable. It further relates to a process for assembly of such a bushing to a coaxial cable. Such connectors are known, from German DE-OS Nos. 20 33 083 and DE-PS 10 75 699 for example. The contact bushing of the connector in the former document is a tapering ring, whereas in the latter it is a tapered bushing with outside teeth. Both types of contact bushing are inserted axially between the outer conductor and the dielectric of the cable. The outer conductor is a relatively thick-walled, corrugated or sturdily braided tube that can readily be secured with a clamping ring or similar device.
This type of contact, which simultaneously involves mechanical and electrical connection, is however not possible with coaxial cables that have a thin-walled outer conductor of copper, foil or thin sheet copper for example. Such cables are common today in cable-television distribution networks, where an outer-contact shield is soldered along the cable to make it impermeable to high-frequencies. This shield is too close to the dielectric, which is made of polyethylene or a similar material, for a contact bushing to be inserted between the dielectric and the outer foil conductor without damaging the latter, and proper contact would not be ensured. This is why the jacket, which surrounds the outer conductor, as well as, if necessary, the inner conductor or dielectric has been used in the past to connect the cable mechanically, with electrical contact being made by spring contacts provided on the outer conductor which contacts permit the connector and outer conductor to slide together. Such connectors are disclosed in German Nos. DE-PS 21 33 392, DE-OS 21 34 304 and 23 31 610.
Other cable connectors are known that have mechanisms that clamp onto the conductor and simultaneously perform the functions of making contact and connecting the cable mechanically. This is possible with thin-walled outer conductors that are strong enough, as is the case for some cables with outer conductors of foil. Such cables are fastened by soldering or by clamping with tapering outside ring clamps, or by metal pieces inserted into the jacket to ensure positive contact. Spring and crimping connectors are also well known.
The known methods either require special tools such as crimping tools or have the drawback of damaging the jacket to the extent that it might not be able to resist sufficiently being pulled. Another disadvantage is that these methods result in deformations that lead to increased reflection.
The sliding-contact connectors mentioned above do not of course have these disadvantages, although the outer conductor can not be employed to assist in strain relief.